Re: current input & output ports
Taylor Campbell 17 Jun 2005 04:55 UTC
On Fri, 17 Jun 2005, Alex Shinn wrote:
> How do you propose to give access to stdin and stdout?
Those are two very Unix-centric resources, which is not something I'd
like to see Scheme standardized on except in an interface specifically
to Unix, such as a scsh SRFI. (Note, by the way, that there are
STANDARD-INPUT-WRITER & STANDARD-INPUT-READER already.) However, my
complaint is more with the mechanism of a global 'current input port' &
'current output port' afforded special status among the I/O system so
much so as, for example, to destroy useful argument conventions; as I
suggested, there could still be items in the dynamic environment used
for things like terminal interaction ports, or, in a hypothetical Unix
interface, stdin & stdout ports.
(T, for instance, worked in the way I suggest; it still provided access
to stdio ports via settable procedures STANDARD-INPUT & STANDARD-OUTPUT
as well as potentially separate terminal ports with TERMINAL-INPUT &
TERMINAL-OUTPUT. The I/O-related procedures all required their first
arguments to be ports, except in a couple cases (like PRINT, where the
object being printed could specialize itself); there was no general
'current input port' or 'current output port.')